Self destruction device



July 5, 1960 G. E. GRASER 2,943,573

sELE DESTRUCTION DEVICE Filed Jan. 5, 1959 l -Ej INVENToR. Bill: er' E. Eras BD States of America as represented by the Secretary of the Army Filed Jan. 5, 1959, Ser. No. 785,100

3 Claims. (Cl. 102-75) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a fuse for a projectile and more particularly `a fuze adapted to detonate in response to a grazing or glancing impact of a projectible with the target.

The purpose of a graze fuze is to initiate the main charge when the initial impact is oblique or glancing as well as when the projectile hits the target in a line substantially perpendicular to the surface thereof.V One method of accomplishing this result is to employ a fuze that is responsive to the deceleration caused by the grazing impact, to detonate the charge in the projectile. During a normal flight however the projectile is decelerating continuously shortly after it leaves the barrel. The amplitude of this deceleration during flight will vary and at times is quite large depending on the physical characteristics of the projectile and the characteristics of the propellant charge. Hence proper operation of a graze fuze requires that it be sensitive enough to be actuated in response to relatively small deceleration caused by a glancing impact but not sensitive enough to be actuated by the somewhat smaller deceleration which occurs during flight. More specilically the fuze should be accurately sensitive 'to detonate in the range of l5 gs to 50 gs of deceleration. If the sensitivity of the fuze is substantially less than l gs the fuze may detonate during ight.

A fuze can be designed to theoretically detonate at l5 gs. The diiculty howeveris that when such Ia fuze is actually made it is virtually impossible to produce a fuze that will actually detonate at approximately gs of deceleration. Fur-ther when the same design is employed to produce this fuze in large quantities employing ordinary methods of manufacture, an alarmingly large percentage of the fuzes will not detonate within the desired range rof deceleration (for example 15 gs to 50 gs). More specifically many of the fuzes will detonate during Hight in response to a deceleration substantially less than 15 gs and some will not detonate due to a force of less than 50 gs. This is generally due to critical dimensions, shapes and weights `of elements lof the fuze which must be attained for accurate detonation at l5 gs of deceleration.

Accordingly an object of this invention is to provide a graze fuze that will detonate upon a glancing or grazing impact of the projectile with the target.

Another object of the invention is the provision of a fuze that will detonate accurately at a predetermined amount of deceleration.'

Still `another object of the invention is to provide a graze fuze which will detonate accurately within a predetermined range of deceleration.

A further object of the invention is the provision of a graze fuze which is sensitive enough to detonate in response to a grazing or glancing impact but will not detonate during ight.

A still further object of the invention is to provide a nite States Patent ice Patented July 5, 19Go graze fuze which will detonate in response to the deceleration caused by an oblique or glancing impact but will not detonate in response to the deceleration during ilight.

A still further object of the invention is the provision of a graze fuze which can be mass produced by standard methods of manufacture and having a minimum of variance of detonating characteristics between the fuzes produced.

A still further object of the invention is to provide a graze fuze which can be produced by standard methods of manufacture yet will accurately detonate within a predetermined range of deceleration.

The specific nature of the invention as well as other objects and advantages thereof will be clear from the description of the preferred embodiment shown in the accompanying drawing, in which:

Figure 1 is an elevation view with a partial cross section of the fuze of the invention in unarmed position.

Figure 2 is a partial elevation view of the fuze shown in Figure 1 indicating the armed position before impact in broken lines and after impact in solid lines.

Figure 3 is a left elevation View of the fuze shown in Figure l.

Figure 4 is a sectional view taken through lines 4-4 of Figure l.

Figure 5 is a perspective view of the trigger actuating means and the tiring pin of the fuze shown in Figure 1, and

Figure 6 is a detail section taken through lines 6-6 0f Figure 1.

The preferred embodiment of the invention is illustrated in the drawing and comprises a fuze generally indicated by 1, and as shown in Figure l is assembled in a projectile indicated by 2 in broken lines.

Fuze 1 is contained in a case 3 and consists of a body 4 mounted on a base 5. Operating mechanism for fuze 1 is provided and includes an inertia operated arming means indicated generally by 6, detonating means indicated generally by 7, triggering means indicated generally by 8 'and a firing means generally designated by 9.

Inertia operating mechanism 6 comprises a first lever 10 biased in a counter clockwise direction by a spring 11 and pivoted as at 12 to fuze body 4, and has a nose 13 adapted to be engaged ina notch 14 of a second lever 15,

also biased in a counter clockwise direction by spring 16. Lever 15 is pivoted :on fuze body 4 as at 17 and has a nose 18 normally engaging the under edge of a third lever 19 pivoted to a fuze body 4 as at 20.

Detonating means 7 include a rotor 21 rotatably mounted on shaft 22 in fuze body 4 and is spring wound by spring 23, as seen in Figure 1. A pin 24 is fixed 'at one end of rotor 21 and protrudes through an arcuate slot 25 in fuze body 4 to engage `a rounded end 26 of third lever 19 to normally restrain rotor 21 in its unarmed position. R'otor 21 carries a detonating `element 27 (see Fig. l). A wiping contact element 28 carried by rotor is provided for electrical contact with a contact 29 fixed in fuze body 4 and is connected to an electric source, not shown.

Triggering means 8 is designed to lock the ring means against accidental release and consists of a cam lever 31 pivoted to fuze body 4 as at 32. A weight 33 is carried at the free end of lever 31 and an upward portion of lever 31 is turned inward as at 34 to ride in a groove 25 of rotor 21. Lever 31 is provided with an arcuate notch 35 on its under side. A locking pin 36 is slidably mounted in a bore 37 in fuze body 4 as seen in Fig. 4, and is biased against the inner face of lever 31 by a spring 38. Locking pin 36 is provided at its inner end with a stud 39 normally engaging the ring means 9, as best viewed in Fig. 5.

Firing means 9 comprise a plunger 40 slidably mounted in ,a bore 441 vin fuze body 4, bore 41 being transversely disposed with relation to `bore 37. Plnnger 40 is cap shaped yand is provided with a firing pin 43 centrally disposed on the upper face thereof. A spring 42 is received in the cap shaped plunger 40 and is held in bore 41 by a screw cap 44 closing the rearward end of bore 41. Spring 42 normally biases plunger 40 forwardly in bore 41 and in unarmed position, against stud 39.

Operation When the projectile commences its ight, levers 15 and 19 move counterclockwise in sequence due to acceleration overcoming inertia. Thus, third lever 19 with its rounded end 26 which rides olf pin 24 will permit spring wound rotor 21 to rotate in a counter clockwise direction. Upon reaching its rotational limit dueto pin 24 reaching the opposite end of slot 25, the rotor will be in .armed position with detonator 27 aligned with ring plunger 40 and its pin 43. The fuze is now in an armed but locked position, the Aplunger 40 being held in its -retracted position in bore 41 only by locking pin 36.

Upon grazing lor glancing impact with the target the projectile decelerates due to the impact; cam lever 31 will be moved forward by its weight 33 whereupon the arcuate notch 35, whose circumference has substantially the same diameter as locking pin 36 which is cylindrical, will clear the `locking pin 36 which will move radially and outwardly to free the plunger 40 to fly forward and strike detonator 27 to re the projectile. Upon full impact with a target, the mechanism Works in the same manner, except that the action will he swifter.

Cam lever 31 is relatively long and must move through a surface of substantial distance indicated by F on Figure 6. Thus only a relatively light weight 33 is required at one end thereof to move this surface. This allows the mechanisms to be used in small fuzes, and also lessens necessary weight considerations of the fuze. Further, since the releasing surface must move through the -relatively long distance F, the effect of manufacturing errors in weight and shape will be minimized so that standard production fuzes will detonate at gs with a minimum of variance.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and Vthat various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention, or -the scope of the subjoined claims.

Having thus described my invention, I claim:

1. In a graze fuze for a projectile comprising a fuze body, a cylindrical spring-wound rotor rotatably mounted in said body for rotation from armed to unarmed positions, a detonator element carried by said rotor, a pin fixed to one end of said rotor, an acceleration operated arming means for said fuze comprising a first spring loaded lever pivotally mounted to said body and defining a nose at its free end, a second spring loaded lever pivotally mounted to said body and defining a nose portion and a notch at its free end thereof, said nose on said first lever adapted to engage said notch in said second lever, a third lever pivoted to said body defining a rounded edge at its free end, adapted to engage said pin on said rotor, said nose on said second lever adapted to engage the under edge of said third lever, said first, second and third levers *adapted to move rearwardly and out of their engaged relation upon acceleration overcoming inertia of said projectile audielase Said rotor to rotate to said armed position, a spring biased tiring pin slidably mounted in said body, `and firing means operable upon target impact of said fuze to release said firing lpin to re 'said detonator in said fuze.

2. In a graze fuze for a projectile including a fuze body, a cylindrical spring wound rotor having a circumferentially disposed groove rotatably mounted in said body for rotation from armed to lunarmed positions, a detonator carried by said rotor, acceleration operated arming means for said fuze Ymounted on said `body adapted to releasably engage said rotor, .a spring biased ring vpin slidably mounted -in said boda/,impact responsive triggering means adapted to releasably engage said ring pin, said triggering means comprising ,an elongated cam lever pivoted at one end to said body, said lever defining an inwardly turned portion at its .free .end for engagement with said groove in said rotor, there being an arcuate notch in its under edge thereof, said notch being disposed between said free end and said pivoted end of said lever, a cylindrical spring biased locking pin slidably mounted in said body, said locking pin having its longitudinal axis being disposed at right angles 4to the vlongitudinal axis of said firing pin, said locking pin having a stud integral to one end thereof normally extending into the path of said firing pin, said locking pin having its other end normally engaging said cam lever whereby said locking pin and said tiring pin are held in retracted position, said cam lever adapted to move forward upon impact of said fuze whereby said locking pin will be released when said arcuate notch in said lever rides above said locking pin to release said ring pin to fire said detonator in said rotor.

3. A graze fuze for a projectile comprising, a fuze body, a cylindrical spring lwound rotor rotatably mounted in said body, a detonator carried by said rotor, a firing pin slidably mounted in said fuze body for movement from a rearward safety position spaced from said detonator to a forward firing position in contact with said detonator, a iirst spring means abutting said firing pin tending to force said firing pin to said ring position, a locking pin normally positioned transverse to said tiring pin and in engagement therewith to hold said firing pin in said safety position, said locking pin slidable outwardly to a release position out of contact with said firing pin to effect movement of said firing pin to said tiring position, a second spring means tending to force said locking pin outwardly to ysaid release position, a cam lever pivotally mounted at one end thereof on said body and normally positioned in engagement with the outer end of said locking pin to hold said locking pin in engagement with said firing pin so as to hold said iring pin in said safety position, said cam lever having a weighted portion near the free end thereof, said cam lever adapted to be rotated under iniiuence of said weighted portion upon deceleration, due 11o impact on said projectile, and move out of engagement with said locking pin Ato effect movement of said locking pin out of holding contact with said firing pin.

References Cited in the le of this patent UNITED `STATES PATENTS 1,943,706 Varaud Jan. 16, 1934 2,405,840 Leech Aug. 13, 1946 2,701,527 Granath Feb. 8, 1955 2,850,979 Hardwick Sept. 9, 1958 FOREIGN PATENTS 967,193 France Mar. 22, 1950 l i l l z 

